1. Field of the Invention
This invention generally relates to a multi-plate clutch. More specifically, the present invention relates to a multi-plate clutch with a boss that couples a flywheel and a clutch cover assembly, and that drives a friction connecting plate on the input side.
2. Background Information
A multi-plate clutch is often used in such vehicles as racing cars. Multi-plate clutches generally comprise a flywheel on the engine side, a clutch cover assembly disposed axially apart from the flywheel, and a plurality of input and output members (for example, drive and driven plates) disposed between the flywheel and the pressure plate of the clutch cover assembly. The term xe2x80x9cmulti-plate clutchxe2x80x9d as used herein means a clutch in which more than two output portions are disposed and more than three friction connecting faces are formed by the input member and the output member.
The flywheel and the clutch cover in the multi-plate clutch are typically coupled together by, for example, a cylindrical member. The cylindrical member is disposed on the outer circumferential side of the drive and driven plates. The cylindrical member has a plurality of teeth disposed circumferentially next to one another on the inner circumferential face. The teeth of the cylindrical member extend in an axial direction on the inner circumferential face and engage outer circumferential teeth of the drive plate. This engagement makes the drive plate axially movable and circumferentially unmovable against the cylindrical member. In other words, a torque is transmitted from the flywheel to the drive plate via the cylindrical member.
Some multi-plate clutches have a boss not only used to couple the flywheel and the clutch cover together, but also used to drive a drive plate. The boss is often a column like member extending in an axial direction, with radially extending spaces being formed in between circumferentially adjacent column like members. A connecting portion is formed on the outer circumference of the drive plate. The connecting portion is inserted in the spaces described above and engages the boss such that it is axially movable and circumferentially non-movable.
The above mentioned conventional multi-plate clutch of a boss-driving type has a boss which is formed in a body with a clutch cover or a flywheel. Some bosses have a plurality of columnar portions.
When the number of friction faces of the multi-plate clutch is changed by the user, the length of the clutch in an axial direction need to be adjusted by exchanging the boss. In that case, either a flywheel or a clutch cover assembly of a multi-plate clutch with the conventional structure need to be exchanged. In addition, when a boss is exchanged because of its abrasion, either a flywheel or a clutch cover assembly need to be exchanged together with the boss. When a boss has a plurality of columnar portions, this typically increases the number of parts and makes it difficult to maintain the accuracy on assembling them.
In view of the above, there exists a need for a multi-plate clutch which overcomes the above mentioned problems in the prior art. This invention addresses this need in the prior art as well as other needs, which will become apparent to those skilled in the art from this disclosure.
An object of the present invention is not only to make it easy to exchange a boss, but also to limit the number of parts needed in a multi-plate clutch with a boss-driving type.
A multi-plate clutch in accordance with one embodiment of the present invention includes an input rotary body, a boss, a clutch cover assembly and a plurality of input-output friction members. The input rotary body includes a friction face. The boss is detachably fixed to the input rotary body. The boss includes an annular portion and a plurality of connecting portions. The connecting portions are integrally formed with the annular portion and extend from the annular portion in an axial direction. Each of the connecting portions is disposed circumferentially next to one another in a circular pattern with a radial pass-through space formed therebetween. The clutch cover assembly includes a clutch cover, a pressure plate and an urging member. The clutch cover is detachably fixed to the boss and faces the friction face in an axial direction. The pressure plate is disposed on the friction face side of the clutch cover. The urging member is supported by the clutch cover and urges the pressure plate toward the friction face side. The input friction member is disposed axially between the friction face and the pressure plate. The input friction member is coupled to the plurality of connecting portions such that they are non-rotatably and axially movably relative to each other. The output friction member is disposed axially between the friction face and the pressure plate. The output friction member forms at least three friction connecting faces in the whole clutch.
In the multi-plate clutch of the present invention, the boss is detachably fixed to both the input rotary body and the clutch cover of the clutch cover assembly. Consequently, when the boss has to be replaced, it is enough to replace only the boss. As a result, since it is not necessary to replace a large member such as the clutch cover assembly and the flywheel, which has to be replaced in the case of a conventional multi-plate clutch, the operation to replace the boss is easy.
In the multi-plate clutch of the present invention, since the boss is a single portion which includes an annular portion and a plurality of connecting portions formed integrally, the number of parts does not need to be increased, and also the accuracy of dimension of parts can be improved.
In the multi-plate clutch of the present invention, the input friction member is coupled to the plurality of connecting portions of the boss non-rotatably and axially movably relative to each other.
In the multi-plate clutch of the present invention, the pressure plate recited above is connected with the plurality of connecting portions of the boss such that they are non-rotatably and axially movably relative to each other.
In the multi-plate clutch of the present invention, the annular portion mentioned above is detachably fixed to one of the input rotary body and the clutch cover, and the plurality of connecting portions is detachably fixed to the other of the input rotary body and the clutch cover.
In the multi-plate clutch of the present invention, the connecting portion mentioned above has the circumferential width smaller than the space that is formed in between the circumferentially adjacent connecting portions.
These and other objects, features, aspects and advantages of the present invention will become apparent to those skilled in the art from the following detailed description, which, taken in conjunction with the annexed drawings, discloses a preferred embodiment of the present invention.